Magnetic core array



Aprll 5, 1966 w, EISEMAN ET AL 3,245,059

MAGNETIC CORE ARRAY Filed May 31. 1962 3 Sheets-Sheet 1 Fig. 2.

WITNESSES I INVENTORS d Wi liom E Eisemon on John C. Donohue.

ATTOR April 5, 1966 w. F. EISEMAN ET AL 3,245,059

MAGNETIC CORE ARRAY Filed May 31, 1962 3 Sheets-Sheet 2 w. F. EISEMAN ETA!- MAGNETIC cons ARRAY April 5, 1966 Filed May 31. 1962 3 Sheets-Sheet 5 United States Patent 3,245,059 MAGNETIC CORE ARRAY William F. Eiseman, North- Linthicum, and lohn C. Donohue, Hanover, Md., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed May 31, 1962, SenNo. 199,097 9 Claims. (Cl. 340174) The present invention relates generally to magnetic core arrays and more particularly relates to a magnetic core array having concentric electrical ground planes.

' Ferrite core memory stacks of the prior art have been formed with the memory planes built by stringing the cores on small wires within a frame. These wires, usually ranging in size from No. 32 to N0. 40, are the only means of support for the cores. Thus, the memory planes are very delicate and are easily damaged.

Another serious problem has been the shielding of one conductor from another when interlaced in a memory stack. pickupwithin a stack. In prior artarrays, the cross talk is reduced by placing electrical ground planes, such as thin sheets of copper or other suitable conducting materials, between the memory. planes. This form of shielding, however, is at best only partially effective; that is, it only shields adjacent memory planes effectively. It is not an effective shield for adjacent conductors within any given memory planes. The core memory stack is a three dimensional array and ground shields of the prior art are planar only.

When multiple aperture cores are used, the problems of wiring and shielding become much worse. In'fact, for any memory stack of sutficient capacity to be at all usable, the actual. mechanical assembly and wiring becomes nearly impossible in fabrication time alone.

* It is, therefore, anobject of the present invention to provide a magnetic core array providing superior shielding and allowing more rapid assembly than prior art core memory stacks.

Another object of the present invention is to provide a magnetic core array having a construction which greatly reduces noise and stray electrostatic pickup in the magnetic cores.

Another object of the present invention is to provide a magnetic array having greatly improved electrical and mechanical properties.

A more specific object of the present invention is to provide a magnetic core array wherein electrostatic shielding is inter-posed between the magnetic core and conductors passing through each core.

Further objects and advantages of the present invention will be readily apparent from the following detailed description taken in conjunction with the drawing, in which:

FIGURE 1 is an illustration presented for a better understanding of the present invention;

FIG. 2 is another schematic illustration presented for a clearer understanding of the present invention;

FIG. 3 is a fragmentary perspective view of an illustrative embodiment of the present invention; and

FIG. 4 is a fragmentary perspective view of an illustrative embodiment of the present invention including a plurality of sections as detailed in FIG. 3.

To provide for electrostatic shielding in accordance with the present invention and as schematically illustrated in FIG. 1, tubes 12 and 14 are inserted through the major aperture 16 of a multiple aperture magnetic core 18. Each .tube is similar in cross-section to hypodermic needles and fabricated of a non-magnetic material such as copper. Conductors are threaded through It is highly desirable to reduce the electrostatic 3,245,059 Patented Apr. 5, 1966 the tubes; A sense conductor '20 and an inhibit conductor 21 are illustrated threaded through the hollow tube 12 while two drive conductors 22 are threaded through the hollow tube 14 The conductors 20 and 22 are properly coated to electrically insulate from each other. The tubes 12 and 14 are electrically insulated by means of a suitable coating on their outer surfaces, both from one another and from the core 18. By grounding each tube at one end a concentric ground shield or concentric ground plane is provided for the conductors 20, 21 and 22 within each respective tube 12 and 14. In such a manner electrostatic shielding is provided for the sense, inhibit and drive lines allowing the elimination of the planar ground sheets of the prior art, while at the same time providing complete shielding even between the various elements of a particular memory plane.

In addition, the crisscrossed tubes 12 and 14 function as a mechanical support for the core 18. The heretofore largely wasted area of the major aperture 16 is elfectively utilized.

interrogate lines or conductors 24 are illustrated extending through minor apertures 26 within the magnetic core 18.

Of course, when a single aperture core is desired to be used the present invention is similarly applicable by extending the tubes 12 and 14 through the single aperture. When desirable, tubes may be used to only enclose the sense and inhibit lines 20 and 21 or only the drive lines 22.

FIG. 2 illustrates a top view of a memory plane in accordance with the present invention. A plurality of magnetic cores 30 are disposed in a memory plane of a frame 31. Extending through each magnetic core 30 are electrically conductive non-magnetic tubes 32 and 34 thereby suspending each core 30 in spacial relationship. Each tube 32 and 34 is stripped of its coat of insulation at one end and secured to one pair of adjacent sides 36 which are grounded at 38. The adjacent sides 36 are formed of sheet-aluminum silver-plated and gold flashed to provide a common ground plane for the memory array. Of course, any suitable conductive material may be used. The opposite end of each tube 32 and 34 are secured to another pair of adjacent sides 40 of the frame 31. The adjacent sides 40 are not electrically grounded but rather made of suitable material to electrically insulate. In such a manner the tubes 32 and 34 are mechanically supported and electrically joined at one end to the common ground 38 through sides 36 and mechanically supported but electrically insulated at their opposite ends by the sides 40.

FIG. 3 illustrates a typical frame of a magnetic core array With the frame 50 having two memory planes, each having a like plurality of magnetic cores 52 and 54 disposed in the first magnetic plane and second magnetic plane respectively. In a magnetic core array disposed in a construction of a successful application each frame 50 contained 64 words of 15 bits each. 32 words are disposed in each memory plane. Each plane has 480 cores. Each bit is physically represented in the frame by a multi-aperture ferrite core. Thus, each frame contained 960 such cores. These frames are in turn turn sub-divided into two horizontal memory planes of 480 cores each, with the planes laying one above the other. Considering a particular memory plane, all the cores 52 are similarly orientated with respect to each other, but are rotated at substantially mechanical degrees to its adjacent memory plane in the frame 50. This orientation scheme is necessary to achieve the correct polarities (cancellation) in the wiring of the frame.

The wiring of a typical core 52 is as follows: The sense and inhibit wires as well as the digit winding wires are enclosed in a thin-copper tube, each tube passes through the major aperture of those cores that represent the same bit in each word in a plane. The cores are set at substantially. 45 mechanical degrees to the axis of the tubing passing 'therethrough to permit the right windings to pass through all the bits of each word. The interrogate drives or conductors 24, which are unshielded, pass through one of the minor apertures of all the cores in one word and then are returned through another minor aperture to terminate at the same side of the frame where they began.

All terminals used for the termination of the leads are hot tin dipped and stacked into the epoxy boards 60 disposed on all four sides of the frame 50. For purposes of clarity in FIG. 4, two opposite sides only are illustrated for mechanically supporting and electrically joining tubes 34 extending thereacross. Slots are provided in the end pieces of the tubes 34 for interlocking with the slots 7?) in the sides 36 and 40 of the frame 50. Of course, similar construction may be provided for the second pair of opposite sidesas illustrated in FIG. 2. In this manner all the cores contained in a memory plane, together with all their conductors, can be preassembled on a work bench into a mat and then inserted into the frame 50. At the same time fully'functionalframes are obtained that can be individually fabricated and tested before they are assembled into a. stack by means of external jumpers between the terminal boards.

FIG. 4 illustrates a magnetic array wherein four frames are illustrated in a stack with the interconnections between stacks provided'by external jumpers 80 between adjacent terminal boards '60.

It is readily apparent that the present invention provides for a packaging density in a magnetic core array which is greatly increased over constructions of the prior-art since the cores are set endwise instead of flat. The increased density of the magnetic cores thereby provides a smaller overall size improving many electrical propertiessuch as delay characteristics and stray inductances. At the same time that superiorshielding is provided increased mechanical strength and ruggedness is also obtained. During construction of the magnetic array each memory plane can be separately-fabricated by individual personnel. The interconnection of memory planes is readily facilitated by bringing all conductors to the outside edges of vthe memory stack. The magnetic core array can also be expanded at will by merely adding additional frames when greater bit capacity is desirable.

Whilethe'present invention has been described with aparticular degree of exactness for the purposes of illustration, it is to' be understood that all equivalents, alterations and modifications within the spirit and scope of the present invention areherein meant to be included.

We claim as our invention:

1. In a magnetic core array, a plurality of magnetic cores each having at least one aperture; a plurality of electrical conductor means for each aperture; and a plurality of electrostatic shielding tubes extending through an aperture in each said core; at least one conductor means for each respective tube threaded therethrough.

2. In a magnetic core array, a plurality of magnetic cores each having at least one aperture; at least a plurality of conductors for each aperture; aplurality of electrically conductive non-magnetic tubes extending through an aperture and supporting each core in spatial relationship; at

tube respectively; the outer wall of each said tube being electrically insulated; and means for electrically grounding each tube.

4. In a magnetic core array, a plurality of frames disposed in a stack; one side of each frame being electrically grounded; another side of each frame being electrically insulated; a plurality of magnetic cores for each frame each having at least one'aperture; a plurality of electrically conductive non-magnetic tubes each secured at one end to said one side and at the other end to said another side; each non-magnetic tube'extending through an aperture of some of said magnetic cores; an electrical conducting means extending through said tubes.

5. In a magnetic core array, a plurality of frames disposed in a stack; one pair of adjacent sides of each frame electrically grounded; the other pair of adjacent sides of each frame electrically insulated; a plurality of magnetic cores for each frame each having at least one aperture; a plurality of electrically conductive non-magnetic tubes each secured to one side of each pair of adjacent sides and each extending through an aperture of some of said magnetic cores; each said tube being electrically connected to said one pair of adjacent sides.

6. In a magneticcore array, a plurality of frames disposed in astack; one pair of adjacent sides of each frame electrically grounded; the other pair of adjacent sides of each frame electrically insulated; a plurality of magnetic cores for each frame each having at least one aperture; a plurality of electrically conductive non-magnetic tubes each secured to one side of each pair of adjacent sides and each extending through an aperture of some of said magnetic cores; each said tube being electrically connected to said one pair of adjacent sides; each magnetic core set at substantially 45 mechanical degrees to the axis of the tubes extending through its aperture.

7. In a magnetic core array, a plurality of frames disposed in a stack; one pair of adjacent sides of each frame electrically grounded; the other pair of adjacent sides of each frame electrically insulated; a plurality of magnetic cores for each frame each having at least one aperture; said plurality of magnetic cores arrayed in parallel planes within each frame; all the cores in any one plane being similarly orientated with respect to each other but rotated substantially mechanical degrees to the cores located in any adjacent plane; a plurality of electrically conductive non-magnetic tubes each secured to one side of each pair of adjacent sides and each extending through an aperture of some of said magnetic cores; each said tube being electrically connected to said one pair of adjacent sides; each magnetic core set at substantially 45 mechanical degrees to the axis of all the tubes extending through its aperture.

8. In a magnetic core array, a plurality of frames disposed in a stack; one pair of adjacent sides of each frame electrically grounded; the other pair of adjacent sides of each frame electrically insulated; a plurality of magnetic cores for each frame each having at least one aperture;

said plurality of magnetic-cores arrayed in parallel planes within each frame; all the cores in any one plane being similarly orientated with respect to each other but rotated substantially 90 mechanical degrees to the cores located in any adjacent plane; a plurality of electrically conductive non-magnetic tubes each secured to one side of each pair of adjacent sides and each extending through an aperture of some of said magnetic cores; each said tube being electrically connected to said one pair of adjacent sides; each magnetic core set at substantially 45 mechanical degrees to the axis of the tubes extending through its aper ture; each said side having slots therein; each said tube having an interlocking slot at each end thereof, whereby all the cores contained in each plane, together with all their conductors can be preassembled into a mat and then inserted into a frame.

9. In a magnetic core array, a plurality of frames disposed in a stack; one pair of adjacent sides of each frame electrically grounded; the other pair of adjacent sides of each frame electrically insulated; a plurality of magnetic cores for each frame each having at least one aperture; said plurality of magnetic cores arrayed in parallel planes similarly orientated with respect to each other but rotated substantially 90 mechanical degrees to the cores located 5 in an adjacent plane; a plurality of electrically conductive non-magnetic tubes each secured to one side of each pair of adjacent sides and each extending through an aperture of some of said magnetic cores; each said tube being electrically connected to said one pair of adjacent sides; each magnetic core set at substantially 45 mechanical degrees to the axis of all the tubes extending through its aperture; terminals disposed on each side of each said frame; and

means for jumping selected terminals from frame to frame in a stack.

References Cited by the Examiner UNITED STATES PATENTS 2,820,216 1/1958 Grottrup 340174 2,945,289 7/1960 Spencer 340174 X 3,026,494 3/ 1962 Anderson 340-174 3,026,494 3/1962 Anderson 340174 10 3,175,200 3/1965 Hoffman 340-174 IRVING L. SRAGOW, Primary Examiner.

R. J. McCLOSKEY, H. D. VOLK, Assistant Examiners. 

6. IN A MAGNETIC CORE ARRAY, A PLURALITY OF FRAMES DISPOSED IN A STACK; ONE PAIR OF ADJACENT SIDES OF EACH FRAME ELECTRICALLY GROUNDED; THE OTHER PAIR OF ADJACENT SIDES OF EACH FRAME ELECTRICALLY INSULATED; A PLURALITY OF MAGNETIC CORES FOR EACH FRAME EACH HAVING AT LEAST ONE APERTURE; A PLURALITY OF ELECTRICALLY CONDUCTIVE NON-MAGNETIC TUBES EACH SECURED TO ONE SIDE OF EACH PAIR OF ADJACENT SIDES 